Layman's Fan Bus Pt.2: The Voltage Switch
-- By: GideonX
Please note: I do not take responsibility for your
stupidty, if you break something that you paid a lot for, tough
luck. I told you to be careful.
This guide is not meant to be an electricians
ideal way of explaining things. This is just a fast write up on a
very simple voltage switching that people with no real 'electrical'
knowledge can do. With that outta the way, here goes. Please check
out my very recent fan bus tutorial.
This item is an important part of the switching process.
Fan wire clutter has gotten to an all time low in
my case. Air flow has greatly improved because of the lessen amount
of Molex connectors clogging up real useful air flow real estate.
Now with all this fine fan tuning at your fingertip, you still
notice that for some reason you still can't hear your favorite Elton
John mp3 because of the constant wurring in the background. You got
it, your fan is causing noise pollution. So here is where the fun
begins, how do I make it quieter? Simple, use a switch or rheostat
to vary the voltage going to the fan. What does this all mean? If
you read on the labels of most fans, it states 12VAC or something to
that extent. This means the max voltage that that single fan can
take is 12volts. I assume anything above that will equal coco krispy
fans. So to get the 12 volts, the fan is powered most of the time by
the nice molex that has connectors with the following voltages:
The yellow wire carries the 12 volts which you
will notice is usally connected to the red wire of the fan. The
black wire is then connected to the ground. Now how much juice is
required to actually run this thing? Twelve volts is the recommended
voltage to attain maximum rpms and cfms. What if I got 20 gazzillion
fans and I don't care that my fans are spinning slower thus causing
less noise? Unbeknowst (is that a word? omfg...) to most people is
that most fans can start up at 5 volts. I tested 6 fans 60mm all the
way to 120mms and they start up fine at 5v. Now how can we use this
to our advantage? We stick a switch on the power line that allows us
to select either 5 or 12 volts! How do we do this? Switches!!!
What are you talking about? Switches?? Huh? Thats
right, go to your local Radio Shack and pick up these fine things:
Here is the list of items that I purchased :
Now on with the tools and supplies I will be
using. Here they are :
- Any type of Single Pole, Double Throw (SPDT) Switch - $1.99
- Fan Bus (you better have
made this first or all hell will break lose)
- Dremel Multi-Pro Variable (The third time i've used it!
- Soldering Iron
- Hair Dryer
- Philips Screwdriver
- Panaflo 80mm fans with bare leads (My test fan, love these
-- Next: Insane Wiring!